# -*- coding: UTF-8 -*-
# Copyright (c) 2007 - 2010, Pascal Volk
# See COPYING for distribution information.

"""
    VirtualMailManager.Domain

    Virtual Mail Manager's Domain class to manage e-mail domains.
"""

import os
import re
from random import choice

from VirtualMailManager.constants.ERROR import \
     ACCOUNT_AND_ALIAS_PRESENT, ACCOUNT_PRESENT, ALIAS_PRESENT, \
     DOMAIN_ALIAS_EXISTS, DOMAIN_EXISTS, DOMAIN_INVALID, DOMAIN_TOO_LONG, \
     NO_SUCH_DOMAIN
from VirtualMailManager.errors import DomainError as DomErr
from VirtualMailManager.Transport import Transport


MAILDIR_CHARS = '0123456789abcdefghijklmnopqrstuvwxyz'
RE_DOMAIN = re.compile(r"^(?:[a-z0-9-]{1,63}\.){1,}[a-z]{2,6}$")
_ = lambda msg: msg


class Domain(object):
    """Class to manage e-mail domains."""
    __slots__ = ('_directory', '_gid', '_name', '_transport', '_dbh', '_new')

    def __init__(self, dbh, domainname):
        """Creates a new Domain instance.

        Loads all relevant data from the database, if the domain could be
        found.  To create a new domain call the methods set_directory() and
        set_transport() before save().

        A DomainError will be thrown when the *domainname* is the name of
        an alias domain.

        Arguments:

        `dbh` : pyPgSQL.PgSQL.Connection
          a database connection for the database access
        `domainname` : basestring
          The name of the domain
        """
        self._name = check_domainname(domainname)
        self._dbh = dbh
        self._gid = 0
        self._transport = None
        self._directory = None
        self._new = True
        self._load()

    def _load(self):
        """Load information from the database and checks if the domain name
        is the primary one.

        Raises a DomainError if Domain._name isn't the primary name of the
        domain.
        """
        dbc = self._dbh.cursor()
        dbc.execute('SELECT dd.gid, tid, domaindir, is_primary FROM '
                    'domain_data dd, domain_name dn WHERE domainname = %s AND '
                    'dn.gid = dd.gid', self._name)
        result = dbc.fetchone()
        dbc.close()
        if result:
            if not result[3]:
                raise DomErr(_(u"The domain '%s' is an alias domain.") %
                             self._name, DOMAIN_ALIAS_EXISTS)
            self._gid, self._directory = result[0], result[2]
            self._transport = Transport(self._dbh, tid=result[1])
            self._new = False

    def _set_gid(self):
        """Sets the ID of the domain - if not set yet."""
        assert self._gid == 0
        dbc = self._dbh.cursor()
        dbc.execute("SELECT nextval('domain_gid')")
        self._gid = dbc.fetchone()[0]
        dbc.close()

    def _has(self, what):
        """Checks if aliases or accounts are assigned to the domain.

        If there are assigned accounts or aliases True will be returned,
        otherwise False will be returned.

        Argument:

        `what` : basestring
            "alias" or "users"
        """
        assert what in ('alias', 'users')
        dbc = self._dbh.cursor()
        if what == 'users':
            dbc.execute("SELECT count(gid) FROM users WHERE gid=%s", self._gid)
        else:
            dbc.execute("SELECT count(gid) FROM alias WHERE gid=%s", self._gid)
        count = dbc.fetchone()
        dbc.close()
        return count[0] > 0

    def _chk_delete(self, deluser, delalias):
        """Checks dependencies for deletion.

        Arguments:
        deluser -- ignore available accounts (bool)
        delalias -- ignore available aliases (bool)
        """
        if not deluser:
            hasuser = self._has('users')
        else:
            hasuser = False
        if not delalias:
            hasalias = self._has('alias')
        else:
            hasalias = False
        if hasuser and hasalias:
            raise DomErr(_(u'There are accounts and aliases.'),
                         ACCOUNT_AND_ALIAS_PRESENT)
        elif hasuser:
            raise DomErr(_(u'There are accounts.'), ACCOUNT_PRESENT)
        elif hasalias:
            raise DomErr(_(u'There are aliases.'), ALIAS_PRESENT)

    def _chk_state(self):
        """Throws a DomainError if the Domain is new - not saved in the
        database."""
        if self._new:
            raise DomErr(_(u"The domain '%s' doesn't exist.") % self._name,
                         NO_SUCH_DOMAIN)

    @property
    def gid(self):
        """The GID of the Domain."""
        return self._gid

    @property
    def name(self):
        """The Domain's name."""
        return self._name

    @property
    def directory(self):
        """The Domain's directory."""
        return self._directory

    def set_directory(self, basedir):
        """Set the path value of the Domain's directory, inside *basedir*.

        Argument:

        `basedir` : basestring
          The base directory of all domains
        """
        assert self._new and self._directory is None
        self._set_gid()
        self._directory = os.path.join(basedir, choice(MAILDIR_CHARS),
                                       str(self._gid))

    @property
    def transport(self):
        """The Domain's transport."""
        return self._transport

    def set_transport(self, transport):
        """Set the transport for the new Domain.

        Argument:

        `transport` : VirtualMailManager.Transport
          The transport of the new Domain
        """
        assert self._new and isinstance(transport, Transport)
        self._transport = transport

    def save(self):
        """Stores the new domain in the database."""
        if not self._new:
            raise DomErr(_(u"The domain '%s' already exists.") % self._name,
                         DOMAIN_EXISTS)
        assert self._directory is not None and self._transport is not None
        dbc = self._dbh.cursor()
        dbc.execute("INSERT INTO domain_data VALUES (%s, %s, %s)", self._gid,
                    self._transport.tid, self._directory)
        dbc.execute("INSERT INTO domain_name VALUES (%s, %s, %s)", self._name,
                    self._gid, True)
        self._dbh.commit()
        dbc.close()
        self._new = False

    def delete(self, deluser=False, delalias=False):
        """Deletes the domain.

        Arguments:

        `deluser` : bool
          force deletion of all available accounts, default `False`
        `delalias` : bool
          force deletion of all available aliases, default `False`
        """
        self._chk_state()
        self._chk_delete(deluser, delalias)
        dbc = self._dbh.cursor()
        for tbl in ('alias', 'users', 'relocated', 'domain_name',
                    'domain_data'):
            dbc.execute("DELETE FROM %s WHERE gid = %d" % (tbl, self._gid))
        self._dbh.commit()
        dbc.close()
        self._gid = 0
        self._directory = self._transport = None
        self._new = True

    def update_transport(self, transport, force=False):
        """Sets a new transport for the Domain.

        If *force* is `True` the new *transport* will be assigned to all
        existing accounts.  Otherwise the *transport* will be only used for
        accounts created from now on.

        Arguments:

        `transport` : VirtualMailManager.Transport
          the new transport
        `force` : bool
          enforce new transport setting for all accounts, default `False`
        """
        self._chk_state()
        assert isinstance(transport, Transport)
        if transport == self._transport:
            return
        dbc = self._dbh.cursor()
        dbc.execute("UPDATE domain_data SET tid = %s WHERE gid = %s",
                    transport.tid, self._gid)
        if dbc.rowcount > 0:
            self._dbh.commit()
        if force:
            dbc.execute("UPDATE users SET tid = %s WHERE gid = %s",
                        transport.tid, self._gid)
            if dbc.rowcount > 0:
                self._dbh.commit()
        dbc.close()
        self._transport = transport

    def get_info(self):
        """Returns a dictionary with information about the domain."""
        self._chk_state()
        dbc = self._dbh.cursor()
        dbc.execute('SELECT gid, domainname, transport, domaindir, '
                    'aliasdomains accounts, aliases, relocated FROM '
                    'vmm_domain_info WHERE gid = %s', self._gid)
        info = dbc.fetchone()
        dbc.close()
        keys = ('gid', 'domainname', 'transport', 'domaindir', 'aliasdomains',
                'accounts', 'aliases', 'relocated')
        return dict(zip(keys, info))

    def get_accounts(self):
        """Returns a list with all accounts of the domain."""
        self._chk_state()
        dbc = self._dbh.cursor()
        dbc.execute('SELECT local_part from users where gid = %s ORDER BY '
                    'local_part', self._gid)
        users = dbc.fetchall()
        dbc.close()
        accounts = []
        if users:
            addr = u'@'.join
            _dom = self._name
            accounts = [addr((account[0], _dom)) for account in users]
        return accounts

    def get_aliases(self):
        """Returns a list with all aliases e-mail addresses of the domain."""
        self._chk_state()
        dbc = self._dbh.cursor()
        dbc.execute('SELECT DISTINCT address FROM alias WHERE gid = %s ORDER '
                    'BY address', self._gid)
        addresses = dbc.fetchall()
        dbc.close()
        aliases = []
        if addresses:
            addr = u'@'.join
            _dom = self._name
            aliases = [addr((alias[0], _dom)) for alias in addresses]
        return aliases

    def get_relocated(self):
        """Returns a list with all addresses of relocated users."""
        self._chk_state()
        dbc = self._dbh.cursor()
        dbc.execute('SELECT address FROM relocated WHERE gid = %s ORDER BY '
                    'address', self._gid)
        addresses = dbc.fetchall()
        dbc.close()
        relocated = []
        if addresses:
            addr = u'@'.join
            _dom = self._name
            relocated = [addr((address[0], _dom)) for address in addresses]
        return relocated

    def get_aliase_names(self):
        """Returns a list with all alias domain names of the domain."""
        self._chk_state()
        dbc = self._dbh.cursor()
        dbc.execute('SELECT domainname FROM domain_name WHERE gid = %s AND '
                    'NOT is_primary ORDER BY domainname', self._gid)
        anames = dbc.fetchall()
        dbc.close()
        aliasdomains = []
        if anames:
            aliasdomains = [aname[0] for aname in anames]
        return aliasdomains


def check_domainname(domainname):
    """Returns the validated domain name `domainname`.

    Throws an `DomainError`, if the domain name is too long or doesn't
    look like a valid domain name (label.label.label).

    """
    if not RE_DOMAIN.match(domainname):
        domainname = domainname.encode('idna')
    if len(domainname) > 255:
        raise DomErr(_(u'The domain name is too long'), DOMAIN_TOO_LONG)
    if not RE_DOMAIN.match(domainname):
        raise DomErr(_(u"The domain name '%s' is invalid") % domainname,
                     DOMAIN_INVALID)
    return domainname


def get_gid(dbh, domainname):
    """Returns the group id of the domain *domainname*.

    If the domain couldn't be found in the database 0 will be returned.
    """
    domainname = check_domainname(domainname)
    dbc = dbh.cursor()
    dbc.execute('SELECT gid FROM domain_name WHERE domainname=%s', domainname)
    gid = dbc.fetchone()
    dbc.close()
    if gid:
        return gid[0]
    return 0


def search(dbh, pattern=None, like=False):
    """'Search' for domains by *pattern* in the database.

    *pattern* may be a domain name or a partial domain name - starting
    and/or ending with a '%' sign.  When the *pattern* starts or ends with
    a '%' sign *like* has to be `True` to perform a wildcard search.
    To retrieve all available domains use the arguments' default values.

    This function returns a tuple with a list and a dict: (order, domains).
    The order list contains the domains' gid, alphabetical sorted by the
    primary domain name.  The domains dict's keys are the gids of the
    domains. The value of item is a list.  The first list element contains
    the primary domain name or `None`.  The elements [1:] contains the
    names of alias domains.

    Arguments:

    `pattern` : basestring
      a (partial) domain name (starting and/or ending with a "%" sign)
    `like` : bool
      should be `True` when *pattern* starts/ends with a "%" sign
    """
    if pattern and not like:
        pattern = check_domainname(pattern)
    sql = 'SELECT gid, domainname, is_primary FROM domain_name'
    if pattern:
        if like:
            sql += " WHERE domainname LIKE '%s'" % pattern
        else:
            sql += " WHERE domainname = '%s'" % pattern
    sql += ' ORDER BY is_primary DESC, domainname'
    dbc = dbh.cursor()
    dbc.execute(sql)
    result = dbc.fetchall()
    dbc.close()

    gids = [domain[0] for domain in result if domain[2]]
    domains = {}
    for gid, domain, is_primary in result:
        if is_primary:
            if not gid in domains:
                domains[gid] = [domain]
            else:
                domains[gid].insert(0, domain)
        else:
            if gid in gids:
                if gid in domains:
                    domains[gid].append(domain)
                else:
                    domains[gid] = [domain]
            else:
                gids.append(gid)
                domains[gid] = [None, domain]
    return gids, domains


del _